The heater core will not have an effect on the check engine light. See related question below for more info on misfires and engine light.
I'm not a mechanic / technician but I BELIEVE if the fuel injector is restricted so that the proper air - fuel mixture is not getting to an engine cylinder , that an engine cylinder misfire can occur ( that is only one of the causes of an engine cylinder misfire )
An engine cylinder misfire is what happens when combustion is incomplete. How much it costs to fix will depend on the type of car and the year it was manufactured.
An engine cylinder misfire has been detected
An engine cylinder misfire has been detected on the # 4 engine cylinder
An engine cylinder misfire has been detected in cylinder # 1
the answer is cylinder two misfire
An engine cylinder misfire has been detected in the # 3 engine cylinder
An engine cylinder misfire has been detected
If your check engine light is flashing that means an engine cylinder (s) misfire has been detected what is a engine cylinder misfire and how much bdoes it cost to fix it
The exact cost to fix an engine cylinder misfire on a 2000 Mercury Mystique will depend on the exact type of engine it has, but can cost around $1,000.
Cylinder #1 misfire.
Stop by http://www.coloradofans.com there are different people that have had that problem. you can probably message them personally and see how they got to that problem. P0300= Random/ multiple cylinder misfire detected P0301= Misfire detected- cylinder #1 P0302= Misfire detected- cylinder #2 P0303= Misfire detected- cylinder #3 P0304= Misfire detected- cylinder #4 p0305= Misfire detected- cylinder #5 P.S. These are Diagnostic trouble codes, not vechicle id numbers.